Now this can be the custom gun of the day as the builder of this MP7 custom shows that installing the PolarStar Fusion Engine can be done in smaller bodies such as a MAEG which the Tokyo Marui MP7 MAEG is. The video link was sent to us anonymously so we cannot credit the reader who pointed to us this. As to how the Fusion Engine, it was never explained, and it's stil a work in progress. Nevertheless, the test fire is impressive which means better watch out for someone who brings something like this to a CQB game.